<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script src="js/vue-2.6.10.js"></script>

</head>
<body>
<div id="app">
    <button @click="show=!show">点我</button>
    <ul >
        <li v-for="(u ,index) in users"  v-if="u.age &lt; 15 "  :key="index">
           {{index+1}} --{{u.name}}
        </li>
        <li v-else >
            {{u.name}}
        </li>

        <ul>
            <li v-for="(index,value,key) in person">
                {{key}}---{{value}}--{{index}}
            </li>
        </ul>
    </ul>
   
    <h2 v-show="show">
        hello show!!
    </h2>

</div>
<script type="text/javascript">
  var app=new Vue({
            el:"#app",
            data:{

              show:true,
              users:[
                  {"id":1,"name":"抽烟","age":5},
                  {"id":2,"name":"喝酒","age":51},
                  {"id":3,"name":"烫头","age":15}
              ],

            }
          })
</script>
</body>
</html>